enabled thumbnails for guided tours

- added the Thumbnail deserialized property to the CardItem for guided tours to enable displaying the image sent from the backend

src/components/Learning/GuideGridItem.jsx

@@ -3,14 +3,14 @@ import { img } from '../../assets/home.js';
 import { startGuidedTour } from '../../functions/utility.js';
 import { CardItem } from '../Common/CardItem.jsx';
 
-export function GuideGridItem({ id, Name, Description, Type }) {
+export function GuideGridItem({ id, Name, Description, Type, Thumbnail }) {
     const triggerStartGuidedTourCommand = () => {
         startGuidedTour(Type);
     };
 
     return (
         <CardItem 
-            imageSrc={img} 
+            imageSrc={Thumbnail || img} 
             onClick={triggerStartGuidedTourCommand} 
             tooltipContent={Description} 
             titleText={Name}